Ovarian Transposition Strategy in Patients with Cervical Cancer Who Undergo Pelvic Radiation: Proposal of Ovarian Placement Based on Virtual Simulations

Abstract

Objective: To establish a proposal for the location for ovarian transposition, considering different irradiation techniques and time to ovarian failure. Methods: Patients with cervical cancer in childbearing age submitted to adjuvant radiotherapy were selected. Delineation of simulated positions of the ovaries and pelvic radiation planning was done in CT, with three techniques: 3D conformal radiotherapy, intensity-modulated radiotherapy, and volumetric modulated arc radiotherapy. In order to correlate the ovaries maximal doses with the time to ovarian failure, the authors have used the one adaptation of Wallace model that predicts oocytes survival rates after radiation exposure. Results: Thirteen patients who were being treated between 2008 and 2017 were studied. When the ovaries were positioned 10 cm cranially from the sacral promontory, the pelvic radiation entails a decrease of 20% in the time to ovarian failure compared with that expected for a female at the same age without irradiation exposition. The placement of the ovaries <5 cm cranially from the sacral promontory results in a decrease >90%. There was no difference in time to ovarian failure between the radiation treatment techniques tested: 3D conformal radiotherapy, intensity-modulated radiotherapy, and volumetric modulated arc radiotherapy (p=0.197). Conclusions: The present study, based on virtual simulations, is the first to use the sacral promontory as a reference for a proposal of ovarian location with transposition. The authors have correlated the position of the ovaries and percentage of decrease in time to ovarian failure. These findings can potentially improve the management and counselling of patients with cervical cancer in childbearing age and deserve clinical validation.